1. Field of the Invention
The invention relates to document handling equipment including systems for feeding and transporting documents.
2. Background Art
A typical system for feeding and transporting documents includes a feeder in the document feeding portion of the system, and a series of roller pairs or belts in the document transporting portion of the system. In the feeding portion of the system, the feeder acts to separate and feed documents singly, in order, from a stack. In the transporting portion of the system, the roller pairs and/or belts convey the documents, one at a time, through a track past other processing devices such as readers, printers, and sorters that perform operations on the documents. The feeder is typically a feed wheel, but may take other forms. Further, the components in the transporting portion of the system may take a variety of forms. An existing document feeder is shown in U.S. Pat. No. 6,199,854. That patent describes a document feeder with a variable speed separator.
In existing systems for feeding and transporting documents, operations that depend on the position of the document are generally performed in the transport stage, or transporting portion of the system. For example, U.S. Pat. No. 5,848,784 describes a document separation apparatus. That patent describes the downstream acceleration/deceleration of documents with pinch rollers to adjust document spacing. U.S. Pat. Nos. 5,419,546; 5,437,375; 5,439,506; 5,509,648; 5,671,919; and 5,908,191 describe examples of other document operations.
Document sorting machinery, like check and letter sorters, is usually designed with a track and walls that guide documents down the track path. Drive rollers, with pinch rollers positioned opposite the drive rollers, usually drive the documents. The pinch rollers are usually spring loaded to provide force against the document, thus pushing the document against the drive rollers, propelling the documents down the path or track. Problems arise when documents jam or stops occur in the track due to a variety of reasons. The causes can be torn, damaged or mutilated documents, staples, folded edges, and other causes not related to the documents. For example, stops could be caused by a jam in a downstream module. When these jams and stoppages occur, operators are required to manually remove the documents from the track. This document clearing requires relieving the spring force of the pinch roller on the document against the drive roller.
Another problem of track accessibility occurs when the track has to be cleaned of paper debris and foreign matter like staples and rubber bands. Yet further problems occur when electronic devices positioned in or along the track require cleaning or maintenance or adjustments. The devices include, but are not limited to; magnetic read heads, pressure devices, optical and digital readers and cameras, bar code readers, printers, inkjets and other recognition devices. Drive and pinch rollers are usually in the same area as these devices to provide positive document drive. Drive and pinch rollers also require periodic cleaning due to ink and paper dust build-up on the document contact surfaces, again necessitating track accessibility.
Existing pinch roller retraction approaches in document handling equipment include levers, cams and other mechanisms that retract pinch rollers just enough to release the grip on the document. Other approaches include removable covers and lids, which expose the pinch rollers, and some may be retracted by hand, enough to relieve the spring pressure on the document. Yet other methods include manual track wall removal, when the pinch rollers are fastened to the track walls. The common problem with these approaches is that true and unrestricted access to the track and devices in and around the document track for document removal, cleaning, maintenance and adjustments is not provided. The existing approaches typically do not allow for true physical access, i.e., allowing an operator to reach his hand directly to the affected area, and also providing a visual line of sight to actually see the affected area. These existing approaches are time consuming, which directly has a negative impact on document throughput and productivity.
Additional background information may be found in U.S. Pat. No. 4,630,815.
For the foregoing reasons, there is a need for an improved mechanism for providing access to the track in a document processing system.